Method of Market Participation for Wind/Photovoltaic/ Energy Storage Based on KKT Condition

With the development of renewable energy, the participation of renewable energy together with energy storage in electricity market has become an inevitable choice. The transaction strategy of renewable energy and energy storage has been studied extensively. However, most existing literature regards renewable energy and energy storage as price takers and ignores their impact on market operation. Therefore, in this paper, the equilibrium between electricity market and wind/photovoltaic/energy storage is investigated. A bi-level model considering the market clearing and the operation of wind/photovoltaic/energy storage is proposed. On the upper level, there is a market operation model, which aims to minimize the market operation cost. On the lower-level, there is a wind/photovoltaic/energy storage operation model, which aims to maximize the profits of wind/photovoltaic/energy storage. Karush-Kuhn-Tucker (KKT) condition is used for solving high computational complexity of bi-level model. The model at lower-level is transformed into constraints and put in the upper-level, thereby making the bi-level model become single-level. Then the problem is turned into a linear programming and it can be solved readily. Numerical case based on IEEE system demonstrates that the method we develop can effectively make the accommodation rate of renewable energy higher, improve the benefits of wind/photovoltaic/energy storage and reduce the market operation cost.